1. Field of the Invention
The present invention relates to a wiper device for wiping a trimmed needle thread.
2. Description of the Related Art
Conventionally, sewing machines capable of sewing embroidery are provided with a cloth presser mechanism to drive the cloth presser to press work cloth on performing embroidery sewing, a thread trimmer device to trim a sewing thread on completing the sewing procedure and a thread wiping mechanism to wipe up the trimmed sewing thread with a wiper member have been reduced to practice.
JP-A-2003-103080 discloses a sewing machine of the above-described type, for example. In the vicinity of a bottom surface of a needle plate of a sewing machine bed, a thread trimming device is provided for automatically trimming a needle thread and a bobbin thread. On a head of the sewing machine above the sewing machine bed, a thread wiping device is provided which pulls out the needle thread connected to the sewing needle by lifting the needle thread onto the needle plate.
To describe the operation of the thread wiping device, when the wiper is driven by a wiper drive mechanism with a needle bar and the cloth presser in lifted position, the needle thread trimmed by the thread trimming device is hooked on a wiper hook to be pulled out of the work cloth and above the needle plate. Then the needle thread is further held by a needle thread retainer.
Also a wiper device of a sewing machine disclosed in JP-U-6-52782 includes a wiper body rotatably supported by a sewing machine frame, a presser to press the work piece to be sewn, a vertically moving unit to be vertically moved with the presser, and a connecting link having one end contacting an upper end of the vertically moving unit, and the other end connected to the wiper body. In this wiper device, the wiping of the sewing thread is actuated by lifting the presser of the sewing machine, which in turn lifts the vertically moving unit contacting the presser. Then, the lifting of the vertically moving unit moves a lower end of the wiper body towards the sewing needle via the connection link to wipe up the sewing thread.
A thread wiping device disclosed in JP-A-2003-103080 is provided in a main body of the sewing machine, and the drive of a wiper is controlled by a wiper drive mechanism in synchronization with the thread trimming movement, thereby leading to increased complexity, size and cost.
In the wiper device in the sewing machine disclosed in JP-U-6-52782, the wiper body moves in conjunction with the vertical movement of the presser and the wiper body is lifted by the lifting of the presser. Therefore, for example, in case the presser is lifted without trimming the needle thread, the needle thread is forcibly pulled by the wiper body, which leads to a problem of deformation of the wiper body and sewing needle.